#include "util/sha1.h"

#include <string.h>

#include <iostream>
#include <sstream>

#include "util/string_util.h"

namespace qcloud_cos {

Sha1::Sha1() { ShaInit(&m_sha); }

Sha1::~Sha1() {}

void Sha1::Append(const char *data, unsigned int size) {
  ShaUpdate(&m_sha, (SHA_BYTE *)data, size);
}

std::string Sha1::Final() {
  char key[SHA_DIGESTSIZE] = {0};
  ShaFinal((unsigned char *)key, &m_sha);

  char out[64] = {0};
  ShaOutput((unsigned char *)key, (unsigned char *)out);

  return out;
}

/* UNRAVEL should be fastest & biggest */
/* UNROLL_LOOPS should be just as big, but slightly slower */
/* both undefined should be smallest and slowest */

#define UNRAVEL
/* #define UNROLL_LOOPS */

/* SHA f()-functions */

#define f1(x, y, z) ((x & y) | (~x & z))
#define f2(x, y, z) (x ^ y ^ z)
#define f3(x, y, z) ((x & y) | (x & z) | (y & z))
#define f4(x, y, z) (x ^ y ^ z)

/* SHA constants */

#define CONST1 0x5a827999L
#define CONST2 0x6ed9eba1L
#define CONST3 0x8f1bbcdcL
#define CONST4 0xca62c1d6L

/* truncate to 32 bits -- should be a null op on 32-bit machines */

#define T32(x) ((x)&0xffffffffL)

/* 32-bit rotate */

#define R32(x, n) T32(((x << n) | (x >> (32 - n))))

/* the generic case, for when the overall rotation is not unraveled */

#define FG(n)                                                \
  T = T32(R32(A, 5) + f##n(B, C, D) + E + *WP++ + CONST##n); \
  E = D;                                                     \
  D = C;                                                     \
  C = R32(B, 30);                                            \
  B = A;                                                     \
  A = T

/* specific cases, for when the overall rotation is unraveled */

#define FA(n)                                                \
  T = T32(R32(A, 5) + f##n(B, C, D) + E + *WP++ + CONST##n); \
  B = R32(B, 30)

#define FB(n)                                                \
  E = T32(R32(T, 5) + f##n(A, B, C) + D + *WP++ + CONST##n); \
  A = R32(A, 30)

#define FC(n)                                                \
  D = T32(R32(E, 5) + f##n(T, A, B) + C + *WP++ + CONST##n); \
  T = R32(T, 30)

#define FD(n)                                                \
  C = T32(R32(D, 5) + f##n(E, T, A) + B + *WP++ + CONST##n); \
  E = R32(E, 30)

#define FE(n)                                                \
  B = T32(R32(C, 5) + f##n(D, E, T) + A + *WP++ + CONST##n); \
  D = R32(D, 30)

#define FT(n)                                                \
  A = T32(R32(B, 5) + f##n(C, D, E) + T + *WP++ + CONST##n); \
  C = R32(C, 30)

/* do SHA transformation */

static void ShaTransform(SHA_INFO *sha_info) {
  int i;
  SHA_BYTE *dp;
  SHA_LONG T, A, B, C, D, E, W[80], *WP;

  dp = sha_info->data;

/*
the following makes sure that at least one code block below is
traversed or an error is reported, without the necessity for nested
preprocessor if/else/endif blocks, which are a great pain in the
nether regions of the anatomy...
*/
#undef SWAP_DONE

#if (SHA_BYTE_ORDER == 1234)
#define SWAP_DONE
  for (i = 0; i < 16; ++i) {
    T = *((SHA_LONG *)dp);
    dp += 4;
    W[i] = ((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
  }
#endif /* SHA_BYTE_ORDER == 1234 */

#if (SHA_BYTE_ORDER == 4321)
#define SWAP_DONE
  for (i = 0; i < 16; ++i) {
    T = *((SHA_LONG *)dp);
    dp += 4;
    W[i] = T32(T);
  }
#endif /* SHA_BYTE_ORDER == 4321 */

#if (SHA_BYTE_ORDER == 12345678)
#define SWAP_DONE
  for (i = 0; i < 16; i += 2) {
    T = *((SHA_LONG *)dp);
    dp += 8;
    W[i] = ((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
    T >>= 32;
    W[i + 1] = ((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
               ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
  }
#endif /* SHA_BYTE_ORDER == 12345678 */

#if (SHA_BYTE_ORDER == 87654321)
#define SWAP_DONE
  for (i = 0; i < 16; i += 2) {
    T = *((SHA_LONG *)dp);
    dp += 8;
    W[i] = T32(T >> 32);
    W[i + 1] = T32(T);
  }
#endif /* SHA_BYTE_ORDER == 87654321 */

#ifndef SWAP_DONE
#error Unknown byte order -- you need to add code here
#endif /* SWAP_DONE */

  for (i = 16; i < 80; ++i) {
    W[i] = W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16];
#if (SHA_VERSION == 1)
    W[i] = R32(W[i], 1);
#endif /* SHA_VERSION */
  }
  A = sha_info->digest[0];
  B = sha_info->digest[1];
  C = sha_info->digest[2];
  D = sha_info->digest[3];
  E = sha_info->digest[4];
  WP = W;
#ifdef UNRAVEL
  FA(1);
  FB(1);
  FC(1);
  FD(1);
  FE(1);
  FT(1);
  FA(1);
  FB(1);
  FC(1);
  FD(1);
  FE(1);
  FT(1);
  FA(1);
  FB(1);
  FC(1);
  FD(1);
  FE(1);
  FT(1);
  FA(1);
  FB(1);
  FC(2);
  FD(2);
  FE(2);
  FT(2);
  FA(2);
  FB(2);
  FC(2);
  FD(2);
  FE(2);
  FT(2);
  FA(2);
  FB(2);
  FC(2);
  FD(2);
  FE(2);
  FT(2);
  FA(2);
  FB(2);
  FC(2);
  FD(2);
  FE(3);
  FT(3);
  FA(3);
  FB(3);
  FC(3);
  FD(3);
  FE(3);
  FT(3);
  FA(3);
  FB(3);
  FC(3);
  FD(3);
  FE(3);
  FT(3);
  FA(3);
  FB(3);
  FC(3);
  FD(3);
  FE(3);
  FT(3);
  FA(4);
  FB(4);
  FC(4);
  FD(4);
  FE(4);
  FT(4);
  FA(4);
  FB(4);
  FC(4);
  FD(4);
  FE(4);
  FT(4);
  FA(4);
  FB(4);
  FC(4);
  FD(4);
  FE(4);
  FT(4);
  FA(4);
  FB(4);
  sha_info->digest[0] = T32(sha_info->digest[0] + E);
  sha_info->digest[1] = T32(sha_info->digest[1] + T);
  sha_info->digest[2] = T32(sha_info->digest[2] + A);
  sha_info->digest[3] = T32(sha_info->digest[3] + B);
  sha_info->digest[4] = T32(sha_info->digest[4] + C);
#else /* !UNRAVEL */
#ifdef UNROLL_LOOPS
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(1);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(2);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(3);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
  FG(4);
#else  /* !UNROLL_LOOPS */
  for (i = 0; i < 20; ++i) {
    FG(1);
  }
  for (i = 20; i < 40; ++i) {
    FG(2);
  }
  for (i = 40; i < 60; ++i) {
    FG(3);
  }
  for (i = 60; i < 80; ++i) {
    FG(4);
  }
#endif /* !UNROLL_LOOPS */
  sha_info->digest[0] = T32(sha_info->digest[0] + A);
  sha_info->digest[1] = T32(sha_info->digest[1] + B);
  sha_info->digest[2] = T32(sha_info->digest[2] + C);
  sha_info->digest[3] = T32(sha_info->digest[3] + D);
  sha_info->digest[4] = T32(sha_info->digest[4] + E);
#endif /* !UNRAVEL */
}

void ShaInit(SHA_INFO *sha_info) {
  sha_info->digest[0] = 0x67452301L;
  sha_info->digest[1] = 0xefcdab89L;
  sha_info->digest[2] = 0x98badcfeL;
  sha_info->digest[3] = 0x10325476L;
  sha_info->digest[4] = 0xc3d2e1f0L;
  sha_info->count_lo = 0L;
  sha_info->count_hi = 0L;
  sha_info->local = 0;
}

/* update the SHA digest */
void ShaUpdate(SHA_INFO *sha_info, SHA_BYTE *buffer, int count) {
  int i;
  SHA_LONG clo;

  clo = T32(sha_info->count_lo + ((SHA_LONG)count << 3));
  if (clo < sha_info->count_lo) {
    ++sha_info->count_hi;
  }
  sha_info->count_lo = clo;
  sha_info->count_hi += (SHA_LONG)count >> 29;
  if (sha_info->local) {
    i = SHA_BLOCKSIZE - sha_info->local;
    if (i > count) {
      i = count;
    }
    memcpy(((SHA_BYTE *)sha_info->data) + sha_info->local, buffer, i);
    count -= i;
    buffer += i;
    sha_info->local += i;
    if (sha_info->local == SHA_BLOCKSIZE) {
      ShaTransform(sha_info);
    } else {
      return;
    }
  }
  while (count >= SHA_BLOCKSIZE) {
    memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
    buffer += SHA_BLOCKSIZE;
    count -= SHA_BLOCKSIZE;
    ShaTransform(sha_info);
  }
  memcpy(sha_info->data, buffer, count);
  sha_info->local = count;
}

/* finish computing the SHA digest */
void ShaFinal(unsigned char digest[20], SHA_INFO *sha_info) {
  int count;
  SHA_LONG lo_bit_count, hi_bit_count;

  lo_bit_count = sha_info->count_lo;
  hi_bit_count = sha_info->count_hi;
  count = (int)((lo_bit_count >> 3) & 0x3f);
  ((SHA_BYTE *)sha_info->data)[count++] = 0x80;
  if (count > SHA_BLOCKSIZE - 8) {
    memset(((SHA_BYTE *)sha_info->data) + count, 0, SHA_BLOCKSIZE - count);
    ShaTransform(sha_info);
    memset((SHA_BYTE *)sha_info->data, 0, SHA_BLOCKSIZE - 8);
  } else {
    memset(((SHA_BYTE *)sha_info->data) + count, 0, SHA_BLOCKSIZE - 8 - count);
  }
  sha_info->data[56] = (unsigned char)((hi_bit_count >> 24) & 0xff);
  sha_info->data[57] = (unsigned char)((hi_bit_count >> 16) & 0xff);
  sha_info->data[58] = (unsigned char)((hi_bit_count >> 8) & 0xff);
  sha_info->data[59] = (unsigned char)((hi_bit_count >> 0) & 0xff);
  sha_info->data[60] = (unsigned char)((lo_bit_count >> 24) & 0xff);
  sha_info->data[61] = (unsigned char)((lo_bit_count >> 16) & 0xff);
  sha_info->data[62] = (unsigned char)((lo_bit_count >> 8) & 0xff);
  sha_info->data[63] = (unsigned char)((lo_bit_count >> 0) & 0xff);
  ShaTransform(sha_info);
  digest[0] = (unsigned char)((sha_info->digest[0] >> 24) & 0xff);
  digest[1] = (unsigned char)((sha_info->digest[0] >> 16) & 0xff);
  digest[2] = (unsigned char)((sha_info->digest[0] >> 8) & 0xff);
  digest[3] = (unsigned char)((sha_info->digest[0]) & 0xff);
  digest[4] = (unsigned char)((sha_info->digest[1] >> 24) & 0xff);
  digest[5] = (unsigned char)((sha_info->digest[1] >> 16) & 0xff);
  digest[6] = (unsigned char)((sha_info->digest[1] >> 8) & 0xff);
  digest[7] = (unsigned char)((sha_info->digest[1]) & 0xff);
  digest[8] = (unsigned char)((sha_info->digest[2] >> 24) & 0xff);
  digest[9] = (unsigned char)((sha_info->digest[2] >> 16) & 0xff);
  digest[10] = (unsigned char)((sha_info->digest[2] >> 8) & 0xff);
  digest[11] = (unsigned char)((sha_info->digest[2]) & 0xff);
  digest[12] = (unsigned char)((sha_info->digest[3] >> 24) & 0xff);
  digest[13] = (unsigned char)((sha_info->digest[3] >> 16) & 0xff);
  digest[14] = (unsigned char)((sha_info->digest[3] >> 8) & 0xff);
  digest[15] = (unsigned char)((sha_info->digest[3]) & 0xff);
  digest[16] = (unsigned char)((sha_info->digest[4] >> 24) & 0xff);
  digest[17] = (unsigned char)((sha_info->digest[4] >> 16) & 0xff);
  digest[18] = (unsigned char)((sha_info->digest[4] >> 8) & 0xff);
  digest[19] = (unsigned char)((sha_info->digest[4]) & 0xff);
}

/* compute the SHA digest of a FILE stream */
void ShaOutput(unsigned char digest[20], unsigned char output[40]) {
  int i = 0;
  for (i = 0; i < 20; ++i) {
    sprintf((char *)(output + i * 2), "%02x", digest[i]);
  }
}

const char *ShaVersion(void) {
#if (SHA_VERSION == 1)
  return "SHA-1";
#else
  return "SHA";
#endif
}

}  // namespace qcloud_cos
